Subcutaneous implantation instrument with dissecting tool and method of construction

ABSTRACT

A subcutaneous implantation instrument with dissecting tool and method of construction are described. An incising shaft longitudinally defines a substantially non-circular bore continuously formed to communicatively receive an implantable object and further includes a beveled cutting blade formed on a distal end. A dissecting tool includes a needle tip forming a pair of longitudinal cutting edges progressively defined outwardly from the needle tip planar to the beveled cutting blade and removably affixable to the distal end of the incising shaft through a proximal coupling. A delivery mechanism longitudinally defines a substantially non-circular bore formed to deploy the implantable object into the incising shaft. One goal is to reduce the subcutaneous sensor insertion of implantable objects and devices, such as sensors, having non-conforming shapes to be the functional equivalent of an injection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication, Ser. No. 11/345,617, filed Feb. 1, 2006, pending; which isa continuation of U.S. patent application, Ser. No. 11/025,770, filedDec. 20, 2004, abandoned; which is a continuation of U.S. patentapplication, Ser. No. 10/222,719, filed Aug. 15, 2002, abandoned; whichis a continuation of application Ser. No. 09/644,666 filed Aug. 24, 2000now U.S. Pat. No. 6,436,068, issued Aug. 20, 2002, the priority dates ofwhich are claimed and the disclosures of which are incorporated byreference.

FIELD OF THE INVENTION

The present invention relates in general to subcutaneous implantationinstruments and methods and, in particular, to a subcutaneousimplantation instrument with dissecting tool and method of construction.

BACKGROUND OF THE INVENTION

Health care assessment includes the review and analysis of physiometrycollected and recorded by electronic data sensors. The type and qualityof physiometry can depend upon the type and location of sensor used.External sensors, such as thermometers, blood pressure cuffs, heart ratemonitors, and the like, are limited in the kinds of information, whichthey are able to collect, and can encumber the patient. Implantable insitu sensors can provide a direct stream of recorded physiometry, butare invasive and require surgical implantation.

Recent advances in microchip technology have created a new generation ofhighly integrated, implantable sensors and medical devices, such asimplantable cardioverter defibrillators, pacemakers, and insertable looprecorders. For instance, PCT Application Nos. PCT/GB99/02389, to Habibet al., filed Jul. 22, 1998, pending, and PCT/GB99/02393, to Habib etal., filed Jul. 22, 1998, pending, respectively describe an implantablesensor chip and treatment regiment, the disclosures of which areincorporated by reference. Each sensor chip can collect and transmitphysiometric data by wireless telemetry to a receiver external to abody. Similarly, the emerging Bluetooth wireless communication standard,described athttp://www.bluetooth.com/developer/specification/specification.asp,proposes a low cost, small form factor solution for short range datacommunications, potentially suitable for use in implantable sensortechnology.

Nevertheless, microchip sensors must still be implanted via some form ofsurgical procedure. Minimally invasive implantation using large boreneedles or flat-edged blades is impracticable because sensors,particularly when embodied using microchip technology, favor a prismaticshape with substantially rectangular cross sections that areincompatible with circular bores. As well, large bore needles can coreout flesh, skin, or hide, when used in animals, as the instruments areinserted subcutaneously, which creates a risk of infection. Moreover,wider-tipped instruments, such as a hollow point chisel, can potentiallycause tearing, gouging, or similar injury due to the width of thecutting edge.

In addition, although current surgical implantation approaches attemptto minimize the size of incision and degree of invasiveness,implantation is, at best, costly, time-consuming, traumatic, requiresmultiple instruments and maneuvers, and potentially risky to thepatient. For example, anesthetizing is conventionally performed using atopical or local anesthetic agent on the implantation site.

Subcutaneous implantable sensors offer the best compromise between insitu sensors and external sensors and are potentially insertable with asimple injection, rather than surgical procedure. These sensors aretypically implanted below the dermis in the layer of subcutaneous fat.Several approaches to the subcutaneous implantation of solid materialshave been described.

An insertion and tunneling tool for a subcutaneous wire patch electrodeis described in U.S. Pat. No. 5,300,106, to Dahl et al., issued Apr. 5,1994. The tunneling tool includes a stylet and a peel-away sheath. Thetunneling tool is inserted into an incision and the stylet is withdrawnonce the tunneling tool reaches a desired position. An electrode segmentis inserted into the subcutaneous tunnel and the peel-away sheath isremoved. Although providing a tool for subcutaneous implantation, theDahl device requires an incision into the subcutaneous fat layer andforms an implantation site larger than the minimum sized required by theelectrode segment. Further more, the cylindrical bore precludes theinjection of non-conforming solid sensors or materials.

An implant system for animal identification that includes a device forimplanting an identification pellet in a fat layer beneath the hide orskin of an animal is described in U.S. Pat. No. 4,909,250, to Smith,issued Mar. 20, 1990. The device includes a curved needle-like tube thatterminates at a tapered, sharpened point. An elongated, flexible plungeris slidably received within the needle-like tube. The pointed tip isinserted through the hide or skin and the plunger is actuated to drivethe identification pellet from the tip into the fat layer. However, theSmith device uses an oversized open bore which can cause coring of thehide or flesh.

A trocar for inserting implants is described in PCT Application No.PCT/US99/08353, to Clarke et al., filed Oct. 29, 1999, pending. Animplant retention trocar includes a cannula for puncturing the skin ofan animal and an obturator for delivering the implant. A spring elementreceived within the cannula prevents an implant from falling out duringthe implant process. The cannula has a distal tip design which causes aminimum of trauma and tearing of tissue during implant insertion.However, the distal tip design is specifically directed to cannulashaving a substantially circular bore and thereby limits the size andshape of implant which can be inserted through the Clarke trocar.

An instrument for injecting implants through animal hide is described inU.S. Pat. No. 5,304,119, to Balaban et al., issued Apr. 19, 1994. Theinstrument includes an injector having a tubular body divided into twoadjacent segments with a hollow interior bore. A pair of laterallyadjacent tines extend longitudinally from the first segment to thedistal end of the tubular body. A plunger rod has an exterior diameterjust slightly larger than the interior diameter of the tubular body.With the second segment inserted beneath the animal hide, the push rodis advanced longitudinally through the tubular body, thereby pushing theimplant through the bore. As the implant and rod pass through the secondsegment, the tines are forced radially away from each other, therebydilating or expanding the incision, and facilitating implant. Theinstrument is removed from the incision following implantation. Thoughavoiding the coring of animal hide or flesh, the instrument forms animplantation site larger than the minimum sized required by the implantand causes potentially damaging compaction of the implant against thelaterally adjacent times during implant delivery.

Therefore, there is need for a non-surgical instrument and method forsubcutaneous implantation of sensors and solid materials that preferablydoes not require an incision preparatory to instrument insertion.

There is a further need for a subcutaneous implantation instrument andmethod capable of implanting sensors and other solid materials that arenot readily disposed to implantation through a substantially circularbore.

Moreover, there is a further need for a subcutaneous implantationinstrument and method which is minimally invasive, preferably creatingthe smallest needed implantation site, and capable of implantationwithout exposing the implant to longitudinal stresses.

There is a still further need for an implantation instrument thatprovides a progressive widening of an implantation site. Suchprogressive widening would facilitate the use of wider-tippedinstruments that provide sufficient girth to admit implantable sensorsand medical devices with lowered patient trauma. Preferably, such aninstrument would include provision for application of an anestheticagent.

SUMMARY OF THE INVENTION

An implantation instrument and method of use for implanting sensors andother solid materials in a subcutaneous or other site is provided. Asused herein, “subcutaneous” refers generally to those implantation siteslocated within a body below the skin. The implantation instrumentconsists of an incising shaft attached to a syringe body. The syringebody and incising shaft both define a substantially non-circular hollowbore for accommodating the sensor or solid material. The subcutaneoussite is formed by a cutting edge on the distal end of the incisingshaft. The subcutaneous site can be cleared using a clearing trocarslidably received within the hollow bore. The sensor or solid materialis advanced through the hollow bore and delivered into the subcutaneoussite. The depth of the subcutaneous site can be limited using apenetration limiting mechanism.

One embodiment provides a subcutaneous implantation instrument withdissecting tool and method of construction. An incising shaftlongitudinally defines a substantially non-circular bore continuouslyformed to communicatively receive an implantable object and furtherincludes a beveled cutting blade formed on a distal end. A dissectingtool includes a needle tip forming a pair of longitudinal cutting edgesprogressively defined outwardly from the needle tip planar to thebeveled cutting blade and removably affixable to the distal end of theincising shaft through a proximal coupling. A delivery mechanismlongitudinally defines a substantially non-circular bore formed todeploy the implantable object into the incising shaft.

A further embodiment provides a subcutaneous implantation instrumentwith a scissored dissecting tool assembly and method of construction. Anincising shaft is fashioned to longitudinally define a substantiallynon-circular bore continuously formed to communicatively receive animplantable object and further including a beveled cutting blade formedon a distal end. A dissecting tool assembly is assembled to provide alongitudinally split needle tip to form a pair of blades with cuttingedges progressively defined outwardly from the needle tip. Thedissecting tool assembly further includes a pair of handles that areeach distally attached to one of the blades and pivotably coupled anddisposed for transverse operation. The dissecting tool assembly isremovably affixable to the distal end of the incising shaft. A deliverymechanism is provided to longitudinally define a substantiallynon-circular bore continuously formed to deploy the implantable objectinto the incising shaft.

A further embodiment provides subcutaneous implantation instrumentpackage and method of construction. A non-liquid implantable object isselected. A subcutaneous implantation instrument is packaged with thenon-liquid implantable object and includes an incising shaftlongitudinally defining a substantially non-circular bore continuouslyformed to communicatively receive the implantable object. The incisingshaft further includes a beveled cutting blade formed on a distal end.The subcutaneous implantation instrument further includes a deliverymechanism longitudinally defining a substantially non-circular boreformed to deploy the implantable object into the incising shaft.

A further embodiment provides a method for implanting a non-liquidobject. A subcutaneous implantation site is formed by urging asubcutaneous implantation instrument that includes an incising shaftwith a beveled cutting blade formed on a distal end subdurally to apredetermined depth. The incising shaft longitudinally defines asubstantially non-circular bore. A non-liquid object is deployed intothe subcutaneous implantation site by progressively urging a deliverymechanism distally through a syringe body proximally affixed to theincising shaft to deploy the implantable object into the incising shaftand thence to insert the implantable object into the subcutaneousimplantation site. The incising shaft is withdrawn from the subcutaneousimplantation site, which is subsequently closed.

One principal value of such a subcutaneous implantation instrument andmethod would be to enable the subcutaneous insertion of implantableobjects and devices, such as sensors, without an operating room orspecial procedures room. In essence, the subcutaneous implantationinstrument and method reduce insertion of implantable objects anddevices having non-conforming shapes to be the functional equivalent ofan injection.

Still other embodiments of the present invention will become readilyapparent to those skilled in the art from the following detaileddescription, wherein is described embodiments of the invention by way ofillustrating the best mode contemplated for carrying out the invention.As will be realized, the invention is capable of other and differentembodiments and its several details are capable of modifications invarious obvious respects, all without departing from the spirit and thescope of the present invention. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an instrument for implanting sensors orsolid materials in a subcutaneous or other tissue location in accordancewith the present invention;

FIG. 2A is a longitudinal cross-sectional view of the implantationinstrument with a straight incising shaft;

FIG. 2B is a longitudinal cross-sectional view of the implantationinstrument with a curved incising shaft;

FIG. 3 is a diagrammatic view illustrating the implantation of an objectinto a subcutaneous site;

FIG. 4A is a diagrammatic view illustrating the clearing of asubcutaneous site using the implantation instrument fitted with aclearing trocar in accordance with a further embodiment;

FIG. 4B is a diagrammatic view illustrating the subcutaneousimplantation of an object using the implantation instrument fitted witha pushing stylet in accordance with a further embodiment;

FIGS. 5A-D are transverse cross-sectional views of the implantationinstrument illustrating, by way of example, various bore configurations;

FIG. 6 is a segmented side view of a clearing trocar;

FIG. 7 is a segmented side view of a pushing stylet; and

FIGS. 8A-8B are section views illustrating penetration limitingmechanisms for use with the implantation instrument;

FIG. 9 is a perspective view of an instrument for implanting objects ina subcutaneous or other tissue location in accordance with a furtherembodiment of the present invention;

FIGS. 10A-10C are perspective views of cutting edges formed on distaledges of incising shafts, in accordance with further embodiments;

FIG. 11 is a longitudinal cross-sectional view of a subcutaneousimplantation instrument in accordance with a further embodiment;

FIG. 12 is a top plan view of the subcutaneous implantation instrumentof FIG. 11;

FIGS. 13-15 are transverse cross-sectional views of the dissecting toolassembly of FIG. 11;

FIG. 16 is a longitudinal cross-sectional view of a subcutaneousimplantation instrument in accordance with a still further embodiment;

FIG. 17 is a top plan view of a subcutaneous implantation instrument inaccordance with an even further embodiment; and

FIGS. 18-20 are perspective diagrams showing a method of use for thesubcutaneous implantation instrument in accordance with one embodiment.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of an instrument 10 for implanting objectsin a subcutaneous or other tissue location in accordance with thepresent invention. The implantation instrument 10 consists of twoprincipal groups of components, an incising body consisting of anincising shaft 11 and a syringe body 15, and a delivery assemblyconsisting of a plunger assembly 20. The instrument 10 can be used tonon-surgically implant an object, such as a sensor or monitor, medicaltherapeutic device, or other solid or semi-solid object. The deliveryassembly is received into the syringe body bore by sliding the plungerassembly 20 through proximal bore opening 19. An implantable object isreceived into the syringe body bore. During an implant procedure, theimplantable object is deployed into the incising shaft and thenceinserted subcutaneously into an implantation site by progressive distalurging of the plunger assembly 20, as further described below beginningwith reference to FIG. 18.

The incising shaft 11 is a hollow point chisel that is formed with abeveled and rounded tip 12 that tapers into a surgically sharp cuttingedge 13 formed on a distal edge. The beveled tip 12 includes a distalbore opening 14 through which the implantable object is delivered intothe implantation site.

The implantable object includes medical monitoring and diagnosticdevices, such as an implantable physiometry sensor, and non-medicalmonitoring devices, such as an environmental or activity monitor. Suchsensors generally record data for subsequent retrieval and can beautonomously triggered or triggered manually by the implant recipient.One implantable sensor microchip suitable for use in the presentinvention is described in PCT Application No. PCT/GB99/02389, to Habibet al., filed Jul. 22, 1998, pending, the disclosure of which isincorporated by reference. Such a sensor could be used for monitoringand collecting physiological or chemical measures. A further implantablemonitoring device suitable for use is the Reveal insertable looprecorder, manufactured by Medtronic, Inc., Minneapolis, Minn., which isan implantable heart monitor for diagnosing the causes of syncope andother transient heart symptoms involving rhythm-related disorders, asdescribed in U.S. Pat. No. 5,331,966, issued Jul. 26, 1994 to Bennett etal; U.S. Pat. No. 6,230,059, issued May 8, 2001 to Duffin; and U.S. Pat.No. 6,317,626, issued Nov. 13, 2001 to Warman, the disclosures of whichare incorporated by reference. Other medical monitoring and diagnosticdevices are possible.

The implantable object also includes non-sensor-type implantable medicaldevices, including implantable medical devices for therapeutic uses,such as administering cardiac pacing or rhythm therapy; providingneural, muscle, or organ stimulation; cancer treatment; and deliveringor dosing medication. As well, the present invention has equalapplicability to implantation of other types of non-medical sensors,including location and identification sensors, such as radio frequencyidentification (RFID) tags. Such sensors could include data transmitterswith which to exchange recorded data and instructional signals.

Finally, the implantable object can include solid or semi-solidmaterials, such as a gelatinous drug bolus. In one embodiment, theimplantable object has approximate dimensions of 5 mm by 10 mm by 20 mm,although other dimensions can be equally suitable. The criticaldimension is the cross-sectional profile, that is, the height and width,of the implant, which must conform to passage through the syringe bodyand incising shaft bores. Other non-linear, prismatic shapes are equallyusable provided the implantable object can fit within the confines ofthe syringe body and incising shaft bores. The implant could also befolded or compacted to minimize the cross-sectional profile with theimplant unfolding or expanding upon implantation. As well, the implantis preferably protected against damage by encasement within, forexample, a mannitol pellet in the case of a solid drug delivery systemor epoxy in the case of an implantable sensor or medical device. Othersizes, shapes, and types of non-liquid implantable objects are possible.

The incising shaft 11 is fixably attached to the syringe body 15 throughfrictional, adhesive, or preformed constructive means, as is known inthe art. Both the incising shaft 11 and syringe body 15 define asubstantially non-circular hollow bore extending continuously along ashared longitudinal axis, as further described below with reference toFIGS. 5A-D.

The plunger assembly includes a plunger 16, an interconnecting plungershaft 17 and a plunger end piece 18. The plunger 16 is conformablyshaped to fit within the syringe body bore. The plunger end piece 18facilitates deployment of the plunger assembly through the syringe bodybore and is preferably shaped to fit a thumb or palm impression. In afurther embodiment, the non-circular hollow bore opens to the distal endof the incising shaft 11 and extends only partly through to thereby forma cavity, rather than a tube, but with provision for the sliding of theplunger shaft 17.

In the described embodiment, the implantation instrument 10 is designedfor inexpensive and disposable use utilizing low-cost, sanitizablematerials. The implantation instrument 10 can be used for out-patient ornon-surgical subcutaneous implant and insertion of an implantableobject, as further described below beginning with reference to FIG. 18.The incising shaft 11 can be fashioned from surgical grade stainlesssteel and has the approximate dimensions of approximately 10 mm by 5 mmin cross section. The incising shaft 11 is approximately 50 mm long andthe length can be varied to accommodate different implantation depths.The plunger 16 is formed from plastic and rubber and preferably forms awatertight seal within the syringe body bore and has the approximatedimensions of approximately 8 mm by 3 mm in cross section. The plungershaft 17 and plunger end piece 18 are formed from plastic or similarmaterial. Other materials, as would be recognized by one skilled in theart, could be substituted.

In a further embodiment, the syringe body 15 and plunger assembly can bereplaced by an automated injection system, such as used withimmunization injection guns or similar devices. These devices typicallyemploy compressed air or other inert gases to administer medication inlieu of manual plungers. Other automated variations includespring-loaded and similar mechanical injection systems. The incisingshaft 11 is fixably attached to the automated injection system whichfunctions as a delivery mechanism in place of the syringe body 15 andplunger assembly. Thus, the implant would be pushed through the incisingshaft bore using the compressed air or gas, or mechanical equivalent.

FIG. 2A is a longitudinal cross-sectional view of the implantationinstrument 10 with a straight incising shaft 11. The hollow bore definedby both the incising shaft 11 and the syringe body 15 runs along acommon shared axis. The incising shaft bore 22 is sized to allow theimplant to advance smoothly into the implantation site under the forwardlateral urging of the plunger assembly 20. The syringe body bore 23 mustbe at least as large as the incising shaft bore 22, but can be slightlylarger to accommodate lubricants, anesthetizing agents, or similarcoatings, such as mannitol, applied over the implantable object.

The syringe body 15 preferably includes a circular collar 21, pair ofwinglets, ears, or eyelets, or similar structure, optionally formed on aproximal end of the syringe body 15 to assist a user in depressing theplunger assembly 20.

FIG. 2B is a longitudinal cross-sectional view of the implantationinstrument with a curved incising shaft 24. The curved incising shaft24, as well as the syringe body 15 and related components, are shapedinto a substantially continuous curve along the ventral side. Thecurvature helps regulate the penetration depth of the incising shaftand, in the described embodiment, has an arc of approximately 20degrees.

FIG. 3 is a diagrammatic view illustrating the implantation of animplantable object 28, including a sensor, implantable medical device,such as an implantable cardioverter defibrillator, pacemaker, orinsertable loop recorder, or other solid material into a subcutaneoussite. Other implantable objects are possible. During implantation, theincising shaft 11 is inserted through the dermis 25 and guided into thelayer of subcutaneous fat 26, above the layer of muscle 27, to asubcutaneous implantation site. The implantable object 28 is fed throughthe proximal bore opening 19 or received through the distal bore openingof the syringe body 15. The implantable object 28 is then furtheradvanced through the syringe body bore 23 and the incising shaft bore 22by the plunger 16 into the subcutaneous site. Note that although theforegoing view illustrates an implant into the subcutaneous fat layer,one skilled in the art would appreciate that subcutaneous implantationlocations are not strictly limited to the subcutaneous fat layer and aregenerally termed as those implantation locations situated subdurallywithin a body under the skin. Accordingly, subcutaneous implantationsites further include locations that are intramuscular and submuscular,or within a body cavity, including intrathoracic.

FIG. 4A is a diagrammatic view illustrating the clearing of asubcutaneous site using the implantation instrument 10 fitted with aclearing trocar 29 in accordance with a further embodiment. The clearingtrocar 29, as further described below with reference to FIG. 6, ismounted to its own handle or plunger assembly and has a sharp cuttingtip 30 for optionally clearing a subcutaneous site prior to delivery ofthe implant.

Prior to implantation, the clearing trocar 29 is slidably received-intothe syringe body 15 and is advanced until the cutting tip 30 is evenwith the proximal bore opening 19 of the incising shaft 11. Duringoperation, the incising shaft 11 and clearing trocar 29 are insertedthrough the dermis 25 and guided into the layer of subcutaneous fat 26,above the layer of muscle 27.

The cutting edge 13 of the beveled tip 12 makes an entry incisionthrough the dermis 25 and is laterally pushed into the subcutaneous fat26 until the cutting edge 13 is adjacent to the subcutaneous site. Theclearing trocar 29 is then urged through the subcutaneous fat 26 byadvancement of its handle or plunger assembly to prepare theimplantation site for delivery of the implantable object 28, includingan implantable sensor, medical device, or other solid material. Theclearing trocar 29 is then withdrawn from the subcutaneous site and outof the implantation instrument 10.

FIG. 4B is a diagrammatic view illustrating the subcutaneousimplantation of an implantable object 28 using the implantationinstrument 10 fitted with a pushing stylet 31 in accordance with afurther embodiment. The pushing stylet 31, as further described belowwith reference to FIG. 7, has a blunt tip 32 for advancing theimplantable object 28 through the syringe body bore 23 and incisingshaft bore 22 and into the subcutaneous site. The cross section of thepushing stylet 31 closely conforms to the incising shaft bore 22 whilethe plunger 16 closely conforms to the syringe body bore 23. The pushingstylet 31 thus extends the reach of the plunger assembly 20 and allowsthe syringe body bore 23 to have a different cross-section than theincising shaft bore 22.

The pushing stylet 31 is used while the incising shaft 11 is in situ inthe subcutaneous layer 26. Prior to delivery, the implantable object 28is fed through the proximal bore opening 19 of the syringe body 15 andfurther advanced within the syringe body bore 23 by contact with theplunger 16. The pushing stylet 31 is slidably received into the syringebody 15 and is advanced until the blunt tip 32 contacts the implantableobject 28. During operation, the implantable object 28 is urged throughthe incising shaft bore 22 by the pushing stylet 31 and into thesubcutaneous site by advancement of the plunger assembly. Upon deliveryof the implantable object 28 into the subcutaneous site, the incisingshaft 11 and pushing stylet 31 are withdrawn.

Although operation of the implantation instrument 10 is described withreference to the implantation of sensors or solid materials into asubcutaneous site situated within the layer of subcutaneous fat 26,implantations could also be effected in other subcutaneous,intramuscular, intraperitoneal, intrathoracic, intracranial, intrajoint,as well as other organ or non-subcutaneous sites, as would be recognizedby one skilled in the art. In addition, the foregoing procedure could bemodified to forego the use of the clearing trocar 29 for smallimplantable objects 28. The clearing effect of the clearing trocar 29can be approximated by use of the incising shaft 11 alone whereby theincising shaft 11 is inserted into the subcutaneous site and thenwithdrawn by reverse deployment, thereby forming a slightly overwideimplantation site.

The operations of subcutaneous implantation can be carried out over aplurality of sites and with the same or different implantable objects28. Similarly, several implantable object 28 could be implanted at thesame subcutaneous site during a single implantation operation.

FIGS. 5A-D are transverse cross-sectional views of the implantationinstrument 10 illustrating, by way of example, various boreconfigurations. FIG. 5A illustrates an incising shaft 35 with asubstantially rectangular bore 36. FIG. 5B illustrates an incising shaft37 with a substantially square bore 38. FIG. 5C illustrates an incisingshaft 39 with a substantially oval bore 40. And FIG. 5D illustrates anincising shaft 41 with a substantially hexagonal bore 42. Note thecircumferential shape of the incising shaft need not follow the internalshape of the incising shaft bore. Other bore configurations, includingvariations on oval, rectangular, square, pentagonal, hexagonal,heptagonal, octagonal, and similar equilateral or non-equilateralshapes, are feasible.

In the described embodiment, the rectangular bore 36 has the dimensionsof approximately 10 mm by 5 mm. The syringe body bore 23 has a length ofapproximately 5 cm.

FIG. 6 is a segmented side view of a clearing trocar 45. The clearingtrocar 45 consists of a beveled tip 47 on the distal end of the clearingtrocar 45 and a clearing trocar shaft 46 affixed, either fixably orremovably, to the distal end of a plunger 16.

During a clearing operation, the clearing trocar 45 is fully extendedfrom the distal bore opening 14 of the incising shaft 11. The clearingtrocar shaft 46 is only long enough to clear out the subcutaneous site.The plunger 16 acts as a stop that limits the extent of penetration ofthe clearing trocar 45, thereby preventing the clearing trocar 29 fromincising too deeply into the subcutaneous fat 29. In addition, theclearing trocar 29 is sized to approximate the girth of the incisingshaft bore 22 and will clear a subcutaneous site only as wide asminimally necessary to facilitate implantation of the implantableobject. In the described embodiment, the clearing trocar 45 has a lengthof approximately 2 cm beyond the tip of the syringe body 15.

FIG. 7 is a segmented side view of a pushing stylet 50. The pushingstylet 50 consists of a blunt tip 52 on the distal end of the pushingstylet 50 and a pushing stylet shaft 51 affixed, either fixably orremovably, to the distal end of a plunger 16.

During a delivery operation, the pushing stylet 50 is extended from thedistal bore opening 14 of the incising shaft 11. The pushing styletshaft 51 is only long enough to clear the distal bore opening 14. Theplunger 16 acts as a stop that limits the lateral travel of the pushingstylet 50. In the described embodiment, the pushing stylet 50 has anadditional length of approximately 2 cm beyond the tip of the syringebody 15.

FIGS. 8A-8B are section views illustrating penetration limitingmechanisms for use with the implantation instrument 10. The penetrationlimiting mechanisms limit the depth of penetration of the incising shaft11 and help prevent excessive penetration. FIG. 8A shows a fixedpenetration limiting mechanism consisting of a stopping flange 55attached to the incising shaft 11. The position of the stopping flange55 along the incising shaft 11 can be adjusted by loosening a hold-downscrew 58 and sliding the stopping flange 55 into the desired location.The lower edge of the stopping flange 55 has a bend 57 with an angle τ,preferably between approximately 30° and 60°, thereby forming an elbow56 which stops lateral travel upon contact with the skin.

FIG. 8B shows an adjustable penetration limiting mechanism consisting ofa stopping flange 60 attached a frictional collar 64. The stoppingflange 60 and frictional collar 64 are slidably attached to the incisingshaft 11. An adjustable collar 64, preferably in threaded communication65 with the frictional collar 64, manually stops deployment of thepenetration limiting mechanism by tightening the frictional collar 64against the incising shaft 11. The lower edge of the stopping flange 60has a bend 62 with an angle υ, preferably between approximately 30° and60°, thereby forming an elbow 61 which stops lateral travel upon contactwith the skin.

FIG. 9 is a perspective view of an instrument for implanting objects ina subcutaneous or other tissue location in accordance with a furtherembodiment of the present invention. The instrument is equipped with thestopping flange 55 shown in FIG. 8A. Other forms of penetration limitingmechanisms, both fixed and adjustable, could be used, as would bereadily apparent to one skilled in the art.

In addition to being flat and chisel-like, the cutting edge of theincising shaft can be shaped as a progressive cutting or clearing blade,or a dissecting tool suitable for use in facilitating subcutaneousinsertion. FIGS. 10A-10C are perspective views of progressive cuttingedges 71, 81, 91 formed on distal edges of incising shafts 70, 80, 90 inaccordance with further embodiments. The cutting edge can be shaped tofacilitate subcutaneous insertion, such as when necessary to penetrateareas of thick epidermis, for instance, on the hands or feet, or animalhide. For instance, the cutting edge 71 can be shaped into a point orsemi-point, which can initially pierce and progressively enlarge animplantation site. Similarly, the cutting edge 81 can be shaped into arounded or curved edge, which can also progressively enlarge animplantation site, but without initial piercing. In addition, thecutting edge 91 upwardly curved or angled, which can help shape theimplantation site to more closely follow the contours of the object tobe implanted. Other cutting edge shapes are possible. Moreover,dissecting tools could be used in addition to or in lieu of theprogressive cutting edges, such as a flat or shaped dissecting tool.

FIG. 11 is a longitudinal cross-sectional view of a subcutaneousimplantation instrument 100 in accordance with a further embodiment. Adissecting tool assembly 101 is removably affixed to the distal end ofthe incising shaft 11 with a coupling sheath 103, which can beconstructed as an over sleeve frictionally fit over the incising shaft11, a snap-off assembly that detaches from the incising shaft 11 bytwisting or distal movement, or some other type of coupling that isnon-integral to the incising shaft 11. The dissecting tool assembly 101includes a needle tip 102 that defines a lumen that internallyinterfaces to the bore opening 14 of the incising shaft 11 and which canbe used to inject a local anesthetic agent or other liquid orsemi-liquid substance into the implantation site. The needle tip 102also progressively defines a pair of cutting blades along each outwardfacing edge.

FIG. 12 is a top plan view of the subcutaneous implantation instrument100 of FIG. 11. The cutting blades are oriented longitudinally andplanar to the cutting edge 13 of the incising shaft 11. The cuttingblades provide cutting edges 105, which gradually increase the width ofthe incision made when the implantation instrument 100 is insertedsubcutaneously. The cutting edges 105 can be straight, concave, convex,or a combination thereof.

FIGS. 13-15 are transverse cross-sectional views of the dissecting toolassembly 101 of FIG. 11. On a distal end, the needle tip 102 internallydefines a lumen of approximately 16 French, which tapers outwardly to alarger diameter bore and substantially non-circular bore ofapproximately 30 gauge on the proximal end. The cutting edges 105 becomeincreasingly pronounced towards the proximal end of the needle tip 102.Other lumen, bore sizes, and cutting edge arrangements are possible.

FIG. 16 is a longitudinal cross-sectional view of a subcutaneousimplantation instrument 110 in accordance with a still furtherembodiment. A curved dissecting tool assembly 111 bends in a gradual arc112 upwardly towards the incising blade 11 to facilitate implantation.The curved dissecting tool assembly 111 can be used with either thestraight incising shaft 11 or curved incising shaft 24. The curvatureenables the implantable object to be more easily oriented parallel tothe surface of the skin, rather than at an angle.

FIG. 17 is a top plan view of a subcutaneous implantation instrument 121in accordance with an even further embodiment. A scissored dissectingtool assembly 122 is divided into two halves, which are each attached toa handle 123 that is pivotably mounted 124, in the manner of a pair ofscissors. The handles 123 can be operated outwardly to cause the distalend of the scissored dissecting tool assembly 122 to open andlongitudinally cut into the surrounding tissues, thereby widening theimplantation site. Once the implantation site has been suitably cleared,the scissored dissecting tool assembly 122 remains open and the plungerassembly 20 is progressive urged distally to insert the implantableobject. The scissored dissecting tool assembly 122 can be straight orcurved to facilitate implantation. Other forms of scissored dissectingtool assemblies are possible.

FIGS. 18-20 are perspective diagrams showing a method of use for thesubcutaneous implantation instrument 121 in accordance with oneembodiment. Referring first to FIG. 18, the subcutaneous implantationinstrument 130 can be used for out-patient or non-surgical subcutaneousinsertion of an implantable object, such as an implantable sensor,medical device, or solid material. The implantation instrument 10enables the subcutaneous insertion of implantable objects and devices,such as sensors, without an operating room or special procedures room.The implantation instrument 10 reduce insertion of implantable objectsand devices having non-conforming shapes to be the functional equivalentof an injection.

The subcutaneous implantation instrument 130 can be sold or marketed aspart of a package that combines an implantable object 134 with thesubcutaneous implantation instrument 130, particularly where thesubcutaneous implantation instrument 130 is provided as a single-usedisposable unit. Thus, the subcutaneous implantation instrument 130 canbe offered with an implantable 134 object already disposed within thesyringe body 131, with the entire package sealed ready for use insidesterile packaging (not shown). Alternatively, the subcutaneousimplantation instrument 130 can be offered in combination with animplantable object 134 that is packaged separately.

At the outset of the procedure, an implantation site 137 can be locallyanesthetized using the subcutaneous implantation instrument 130 byfitting the incising shaft 132 with a dissecting tool assembly 136, asprovided in a further embodiment, described above with reference to FIG.11 et seq. The coupling sheath 103 of the dissecting tool assembly 136removably fits over the distal end of the incising shaft 132. Theimplantation site 137 is cleaned and sterilized and the needle tip 102is inserted subcutaneously. The needle tip 102 and cutting blades on thedissecting tool assembly 136 form a progressively larger opening as thesubcutaneous implantation instrument 130 is pressed downward through theskin. The plunger assembly 133 is then pressed distally to inject alocal anesthetic agent into the subcutaneous implantation site.

Referring next to FIG. 19, the dissecting tool assembly 136 is withdrawnfrom the implantation site 137 and removed from the incising shaft 132,thereby exposing the cutting edge of the incising shaft 132. The bareincising shaft 132 is inserted into the previously cleared implantationsite 137 and pressed downward. Depending upon the configuration of thecutting edges 105 of the dissecting tool assembly 136, the cutting edgeof the incising shaft 132 may only need to enlarge the opening, ratherthan clearing a full width opening.

Referring finally to FIG. 20, downward movement of the subcutaneousimplantation instrument 130 is stopped when the appropriate depth forimplantation has been reached and, if necessary, is urged slight back toclear the incising shaft 137 from the actual subcutaneous implantationsite. The plunger assembly 133 is again pressed distally to deploy theimplantable object 134 into the incising shaft 134 and thence to insertthe implantable object 134 into the subcutaneous implantation site. Theincising shaft 132 is withdrawn and the wound is appropriately dressedto complete the implantation procedure. Through use of the method, thesubcutaneous sensor insertion of implantable objects and devices, suchas sensors, having non-conforming shapes is thereby reduced to be thefunctional equivalent of an injection.

While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope of theinvention.

1. A subcutaneous implantation instrument with dissecting tool,comprising: an incising shaft longitudinally defining a substantiallynon-circular bore continuously formed to communicatively receive animplantable object and further comprising a beveled cutting blade formedon a distal end; a dissecting tool comprising a needle tip forming apair of longitudinal cutting edges progressively defined outwardly fromthe needle tip planar to the beveled cutting blade and removablyaffixable to the distal end of the incising shaft through a proximalcoupling; a delivery mechanism longitudinally defining a substantiallynon-circular bore formed to deploy the implantable object into theincising shaft; and a lumen defined longitudinally through needle tip ofthe dissecting tool and proximally interfaced to the delivery mechanism.2. A subcutaneous implantation instrument in accordance with claim 1,wherein the dissecting tool is formed into a curve arced towards theincising shaft.
 3. A subcutaneous implantation instrument in accordancewith claim 1, further wherein the proximal coupling is formed as atleast one of an over sheath and a snap-off assembly.
 4. A subcutaneousimplantation instrument in accordance with claim 1, wherein thelongitudinal cutting edges are formed with at least one of straight,concave, and convex surfaces.
 5. A subcutaneous implantation instrumentin accordance with claim 1, wherein the dissecting tool compriseslongitudinally divided halves, further comprising: a pair of pivotablycoupled handles that are each distally attached to one of thelongitudinally divided halves of the dissecting tool and disposed foroperation transversely to the dissecting tool.
 6. A subcutaneousimplantation instrument in accordance with claim 1, wherein theimplantable object is selected from the group comprising medicalmonitoring and diagnostic devices, non-medical monitoring devices, datacollection monitors, medical therapeutic devices, solid objects, andsemi-solid objects.
 7. A method for constructing a subcutaneousimplantation instrument with dissecting tool, comprising: fashioning anincising shaft to longitudinally define a substantially non-circularbore continuously formed to communicatively receive an implantableobject and to further comprise a beveled cutting blade formed on adistal end; providing a dissecting tool to comprise a needle tip thatforms a pair of longitudinal cutting edges progressively definedoutwardly from the needle tip and be removably affixable to the distalend of the incising shaft through a proximal coupling; attaching adelivery mechanism to longitudinally define a substantially non-circularbore continuously formed to deploy the implantable object into theincising shaft; and defining a lumen longitudinally through needle tipof the dissecting tool and proximally interfaced to the deliverymechanism.
 8. A method in accordance with claim 7, wherein thedissecting tool is formed into a curve arced towards the incising shaft.9. A method in accordance with claim 7, further comprising: forming theproximal coupling as at least one of an over sheath and a snap-offassembly.
 10. A method in accordance with claim 7, wherein thelongitudinal cutting edges are formed with at least one of straight,concave, and convex surfaces.
 11. A method in accordance with claim 7,wherein the dissecting tool comprises longitudinally divided halves,further comprising: providing a pair of pivotably coupled handles thatare each distally attached to one of the longitudinally divided halvesof the dissecting tool and disposed for operation transversely to thedissecting tool.
 12. A method in accordance with claim 7, wherein theimplantable object is selected from the group comprising medicalmonitoring and diagnostic devices, non-medical monitoring devices, datacollection monitors, medical therapeutic devices, solid objects, andsemi-solid objects.
 13. A subcutaneous implantation instrument package,comprising: a non-liquid implantable object; and a subcutaneousimplantation instrument packaged with the non-liquid implantable object,comprising: an incising shaft longitudinally defining a substantiallynon-circular bore continuously formed to communicatively receive theimplantable object and further comprising a beveled cutting blade formedon a distal end; a dissecting tool comprising a needle tip forming apair of longitudinal cutting edges progressively defined outwardly fromthe needle tip planar to the beveled cutting blade and removablyaffixable to the distal end of the incising shaft through a proximalcoupling; a delivery mechanism longitudinally defining a substantiallynon-circular bore formed to deploy the implantable object into theincising shaft; and a lumen defined longitudinally through needle tip ofthe dissecting tool and proximally interfaced to the delivery mechanism.14. A subcutaneous implantation instrument package in accordance withclaim 13, wherein the beveled cutting blade is shaped into at least oneof a point, semi-point, rounded edge, curved edge, upward curve, andangled curve.
 15. A subcutaneous implantation instrument package inaccordance with claim 13, wherein the implantable object is selectedfrom the group comprising medical monitoring and diagnostic devices,non-medical monitoring devices, data collection monitors, medicaltherapeutic devices, solid objects, and semi-solid objects.
 16. A methodfor constructing a subcutaneous implantation instrument package,comprising: selecting a non-liquid implantable object; and packaging asubcutaneous implantation instrument, comprising: fashioning an incisingshaft longitudinally to define a substantially non-circular borecontinuously formed to communicatively receive the implantable objectand further comprising a beveled cutting blade formed on a distal end;including a dissecting tool comprising a needle tip forming a pair oflongitudinal cutting edges progressively defined outwardly from theneedle tip planar to the beveled cutting blade and removably affixableto the distal end of the incising shaft through a proximal coupling;providing a delivery mechanism to longitudinally define a substantiallynon-circular bore formed to deploy the implantable object into theincising shaft; and defining a lumen longitudinally through needle tipof the dissecting tool and proximally interfaced to the deliverymechanism.
 17. A method in accordance with claim 16, further comprising:shaping the beveled cutting blade into at least one of a point,semi-point, rounded edge, curved edge, upward curve, and angled curve.18. A method in accordance with claim 16, wherein the implantable objectis selected from the group comprising medical monitoring and diagnosticdevices, non-medical monitoring devices, data collection monitors,medical therapeutic devices, solid objects, and semi-solid objects.